It is soldered to the board since 2016 (on portables), so no surprises there. Since T2, it is only flash chips anyway, the drive controller is inside the T2.
They nuked the lifeboat connector as well that was potentially useful for actually recovering data if your SSD died. If you lose your CPU, you now lose your SSD.
Is losing a CPU a common enough failure-case that it makes sense to implement fail-safes for? I would think that's pretty low on the list of likely causes of failure.
I mean it's more than CPU - losing power regulators, or anything else that causes your machine not to boot to a DFU mode. Watch Louis Rossman's channel for long enough and you'll see how many possible failure modes there are.
My 2014 MBP died a few years back of power regulator cause, but I was able to pull the SSD and image it in the case that they were unable to repair the device.
I lost three Macbooks in two years from USB controller blow outs, which is a known issue because the part they used is lousy, and it took out the entire storage with it. I had some backups thankfully, but I know people who have lost everything.
So yes, make sure your backup procedure is good.